Developing a theory of developmental bias

Eyespots on the wing of an owl butterfly (Image: Elena Elisseeva via Dreamstime.com)

November 14, 2018

This November 14-16, SFI hosts a three-day international workshop to explore the evolutionary consequences of developmental bias — the tendency of organisms to evolve some phenotypes more readily than others.

“Historically, people have tended to think that selection was what was important and tended to ignore developmental bias, but more and more experimental and theoretical evidence is accumulating for bias,” says organizer Kevin Laland, a professor of biology at the University of St. Andrews and member of SFI’s Science Board.

Laland is one of four organizers of the workshop, which is sponsored through a 2016 grant from the John Templeton Foundation. Attendees include some 30 leading evolutionary and developmental biologists, ecologists, computer scientists, psychologists, paleontologists, and philosophers, who are presenting papers and participating in discussions.

Recent studies are shedding light on how bias and selection work together. For example, despite the great diversity of colorful wing patterns in butterflies, a limited set of basic patterns emerge from the way wing “eyespots” develop. The developmental bias inherent in the way these spots form constrains butterfly phenotypes. The great diversity in nature results from natural selection acting on biased variation. It’s an interaction that allows developmental processes to impose a direction on evolution, says Laland.

Phenotypic plasticity can also play a role in the ongoing interaction between bias and selection. In several animals, stress is known to induce plastic phenotypic changes that have distinct biases. These biased changes may then become stabilized by natural selection.

“What’s really exciting for me,” says Laland, “is to get the people who are changing how we think about evolution through their work, all in one room. This will be the first time. I don’t think there’s ever been a workshop on bias before, so it’s tremendous to get such an authoritative group of people.”